Faecal sludge emptying in Sub-Saharan Africa, South and Southeast Asia: A systematic review of emptying technology choices, challenges, and improvement initiatives

Abstract

The emptying and transport of faecal sludge (FS) is a fundamental aspect of the sanitation service chain and is mostly carried out by private operators who usually face a lot of challenges. Our review assessed how influencing factors and challenges FS emptiers face are linked and in turn how they act as barriers to improvement initiatives. We conducted a systematic review of peer-reviewed journals on FS emptying in sub-Saharan Africa, South and Southeast Asia published between January 2002 and December 2021. Amongst the 37 journals reviewed, accessibility was mostly documented (n = 18) as a factor which affected choice of emptying method, followed by cost (n = 14), quality of service (n = 13) and then sludge thickness (n = 8). We grouped the types of challenges identified from the publications into five categories of financial, technical and institutional (n = 14, each), followed by health (n = 12) and then social challenges (n = 8). Discussions on initiatives (n = 13) used to improve the emptying business were limited to Cost/affordability of sanitation services and access to finance by FS emptiers, which were noted to be the major barriers to effective implementation of these strategies. This review identified the need for sensitizing the public on FS emptying, financial modelling of manual emptying business and a need to study the relationship between perceptions and emptying behavior of users.

Willingness to pay for faecal sludge management services - a scoping review

“…A systematic review has revealed that thickness of sludge affects choices of emptying technology because the thickness varies depending on sanitation facilities. (27) In general, sludge is thicker and denser in unlined pit latrines than in septic tanks and lined pits due to lack of ushing water, which makes mechanical emptying ineffective. Additional work, as well as cost, of adding water may be needed.…”

Urban Sanitation: New Terminology for Globally Relevant Solutions?

“…15 Furthermore, wastewater that is removed from containments (e.g., by vacuum truck) is frequently dumped into the environment, due to difficulties of transporting it via congested road networks, or due to a lack of viable alternatives. 28 The result is that common pathways of exposure are open drains and market-bought produce and street food that are contaminated through washing. 29 A further misconception is that sewer-based systems are analogous to safe and managed sanitation.…”

“…Assumptions about the safe containment of pathogens in onsite land-based treatment cannot be reliably transferred to dilute wastewater in urban areas . Furthermore, wastewater that is removed from containments (e.g., by vacuum truck) is frequently dumped into the environment, due to difficulties of transporting it via congested road networks, or due to a lack of viable alternatives . The result is that common pathways of exposure are open drains and market-bought produce and street food that are contaminated through washing …”

Effectiveness of the Swachh Bharat Mission and barriers to ending open defecation in India: a systematic review

“…Quality assessment was performed by one reviewer and involved describing the level of evidence (Ackley et al, 2008;Brownson et al, 2009;Manga et al, 2023;Muoghalu et al, 2023) and risk of bias (Sterne et al, 2016;Higgins et al, 2022;Conaway et al, 2023) that were then used to rate the overall certainty of the articles. Quality assessment results are provided in Table 2.…”